func fg(ec *EvalCtx, pids ...int) { if len(pids) == 0 { throw(ErrArgs) } var thepgid int for i, pid := range pids { pgid, err := syscall.Getpgid(pid) maybeThrow(err) if i == 0 { thepgid = pgid } else if pgid != thepgid { throw(ErrNotInSameGroup) } } err := sys.Tcsetpgrp(0, thepgid) maybeThrow(err) errors := make([]Error, len(pids)) for i, pid := range pids { err := syscall.Kill(pid, syscall.SIGCONT) if err != nil { errors[i] = Error{err} } } for i, pid := range pids { if errors[i] != OK { continue } var ws syscall.WaitStatus _, err = syscall.Wait4(pid, &ws, syscall.WUNTRACED, nil) if err != nil { errors[i] = Error{err} } else { // TODO find command name errors[i] = Error{NewExternalCmdExit(fmt.Sprintf("(pid %d)", pid), ws, pid)} } } throwCompositeError(errors) }
// Eval sets up the Evaler and evaluates a chunk. The supplied name and text are // used in diagnostic messages. func (ev *Evaler) Eval(op Op, name, text string) error { inCh := make(chan Value) close(inCh) outCh := make(chan Value, outChanSize) outDone := make(chan struct{}) go func() { for v := range outCh { fmt.Printf("%s%s\n", outChanLeader, v.Repr(initIndent)) } close(outDone) }() ports := []*Port{ {File: os.Stdin, Chan: inCh}, {File: os.Stdout, Chan: outCh}, {File: os.Stderr, Chan: BlackholeChan}, } // signal.Ignore(syscall.SIGTTIN) // signal.Ignore(syscall.SIGTTOU) stopSigGoroutine := make(chan struct{}) sigGoRoutineDone := make(chan struct{}) // Set up intCh. ev.intCh = make(chan struct{}) sigCh := make(chan os.Signal) signal.Notify(sigCh, syscall.SIGINT, syscall.SIGQUIT) go func() { closedIntCh := false loop: for { select { case <-sigCh: if !closedIntCh { close(ev.intCh) closedIntCh = true } case <-stopSigGoroutine: break loop } } ev.intCh = nil signal.Stop(sigCh) close(sigGoRoutineDone) }() ret, err := ev.eval(op, ports, name, text) close(outCh) <-outDone close(stopSigGoroutine) <-sigGoRoutineDone if !ret { fmt.Println(falseIndicator) } // Put myself in foreground, in case some command has put me in background. // XXX Should probably use fd of /dev/tty instead of 0. if sys.IsATTY(0) { err := sys.Tcsetpgrp(0, syscall.Getpgrp()) if err != nil { fmt.Println("failed to put myself in foreground:", err) } } return err }
func (cp *compiler) pipeline(n *parse.Pipeline) Op { ops := cp.forms(n.Forms) p := n.Begin() return func(ec *EvalCtx) { var nextIn *Port errorChans := make([]chan Error, len(ops)) // For each form, create a dedicated evalCtx and run asynchronously for i, op := range ops { newEc := ec.fork(fmt.Sprintf("form op %v", op)) if i > 0 { newEc.ports[0] = nextIn } if i < len(ops)-1 { // Each internal port pair consists of a (byte) pipe pair and a // channel. // os.Pipe sets O_CLOEXEC, which is what we want. reader, writer, e := os.Pipe() if e != nil { ec.errorf(p, "failed to create pipe: %s", e) } ch := make(chan Value, pipelineChanBufferSize) newEc.ports[1] = &Port{ File: writer, Chan: ch, CloseFile: true, CloseChan: true} nextIn = &Port{ File: reader, Chan: ch, CloseFile: true, CloseChan: false} } thisOp := op errorChans[i] = make(chan Error) thisErrorChan := errorChans[i] go func() { err := newEc.PEval(thisOp) // Logger.Printf("closing ports of %s", newEc.context) ClosePorts(newEc.ports) thisErrorChan <- Error{err} }() } intCh := make(chan os.Signal) signal.Notify(intCh, syscall.SIGINT) interrupted := make(chan struct{}) cancel := make(chan struct{}, 1) go func() { // When SIGINT is received, sleep for InterruptDeadline before the // closing interrupted channel. select { case <-intCh: case <-cancel: return } select { case <-time.After(InterruptDeadline): case <-cancel: return } close(interrupted) }() // Wait for all forms to finish and collect error returns, unless an // interrupt was received and the form didn't quit within // InterruptDeadline. errors := make([]Error, len(ops)) for i, errorChan := range errorChans { select { case errors[i] = <-errorChan: case <-interrupted: errors[i] = Error{ErrStillRunning} } } // Make sure the SIGINT listener exits. close(cancel) signal.Stop(intCh) // Make sure I am in foreground. if PutInForeground && sys.IsATTY(0) { err := sys.Tcsetpgrp(0, syscall.Getpgrp()) if err != nil { throw(err) } } if !allok(errors) { if len(errors) == 1 { throw(errors[0].inner) } else { throw(multiError{errors}) } } } }